High frequency antennas are known in the art. In one method of making such an antenna, electroplating or electroless plating is used to plate one side of a substrate with an antenna pattern. The pattern is printed on one side of the substrate using a seed ink. Upon printing the pattern, the substrate is then electroplated, forming a metallic antenna over the antenna pattern. Since electroplating (or electroless plating) in such antennas is often a one sided operation, a second operation is needed to connect a strap from one end of the antenna to a second end of the antenna. Additionally, electroplating on seed ink is limited by the distance from a supply rail to the furthest point from the rail. Long distances from the supply rail make for long plating times. Moreover, if a double-sided antenna is to be made, the additional operations of printing a pattern on a second side of the substrate and then electroplating that side also need to be performed.
In another method, a conductive line, without loops, may be formed on the second side of the substrate by printing a conductive line pattern on the second side of the substrate using a seed ink and then later electroplating the second side, thus forming the conductive line. A channel may be formed through a hole in the substrate connecting the conductive line with an antenna formed on the first side of the substrate. The hole is punched through the substrate after the seed ink is printed on the second side of the substrate, but before the conductive line is formed through electroplating.
While the conventional solutions for electroplating or electroless plating of electronic devices are advantageous for their intended purposes, a need still exists for a method for double-sided plating of high frequency electronic devices with a plating time that is comparatively less than that of conventional plating. Additionally, a need exists for a simplified method of making a double-sided device, for example, an antenna used for high frequency devices such as HF or RFID tags. Moreover, a need exists for connecting both sides of a substrate for a double-sided electronic device in a minimal number of operations or steps.
The present invention concerns an electronic device (and in particular, a double sided high frequency antenna) and a process for making the same, utilizing a substrate with pre-formed holes, reducing the number of steps required to form the electronic device.